The LHC [1]} and its experiments are performing very well with a wealth of physics results. In about six years from now the phase of the high-luminosity LHC (HL-LHC) [2]} is foreseen to start. By a ten times higher LHC design luminosity and luminosity levelling the delivery of about 4000 \(\mathrm {fb}^{-1}\)  is envisaged within ten years. The prospect to observe and measure rare processes is driving these
developments. Severe radiation doses and high particle production rates at the HL-LHC result in a challenging environment for the collider experiments. An upgrade or even replacement of several detector components of the ATLAS [3]} and CMS [4]} experiments is anticipated to cope with these circumstances. The aim is for the experiments to have a similar performance as in the Run-2 and Run-3 of the LHC.
In this report several of the detector upgrades and their impact on the physics program of the experiments will be given.
It starts with an overview of the physics program and motivation for the detector upgrades. Details about the upgrade of several sub-detectors will then be discussed and their impact on physics performance objects highlighted. The report closes with prospects for selected physics processes.
